Many potent drugs and drug candidates, especially anticancer drugs, are poorly soluble in water (e.g., tamoxifen, paclitaxel, and curcumin). Their poor solubility results in their low bioavailability and difficulties in preparing dosage forms.
Current attempts to solve this problem are associated with loading poorly soluble drugs (usually hydrophobic molecules) into various nanosized pharmaceutical carriers such as liposomes (drugs are loaded into the hydrophobic membrane of the liposome), micelles (drugs are loaded into the hydrophobic core of the micelle), and oil-in-water emulsions. However, many general problems are associated with these approaches, including relatively low loading efficacy of the drug into the nanocarrier (between 0.5% and 25% by weight, and often below 10% by weight) and sizes on the order of 200 nm to 300 nm.